I would say that if you are inexperienced try going into a local bike shop and ask them if they would be willing to show you. I work at a bike shop and I personally am fine with showing someone how to do something like that as long as its not super busy. Just a tip: try to go in at around 11 am if possible because thats when most bike shops are the least busy. And most of all be polite and considerate. No-one likes a rude, inconsiderate person much less teach them how to do something.
